Artifacts are among the hardest permanents to remove (with some colors unable to remove them at all), so Chocobo Racetrack is likely to stick around once it hits the battlefield
By that point Avatar will have come and gone, which means Avatar Aang will be available to us, too
Until this point they had only been given away as player and judge rewards at various Magic events
With just a couple of weeks of pack openings (and the avalanche of resources that are awarded to new players), you should be ready to start climbing the ladder
Any damage you deal to an opponent or an opponent's permanent is doubled, while any dealt to you or a permanent you control is halved instead
Again, the first mulligan doesn't assure that any of this precise scripting happens, but the second one sure does reduce games to it